The present invention relates to frozen par-fried potato strips comprising about 35% to about 55% moisture which when oven finished have substantially the same internal and surface texture as deep fried French fries. More particularly this invention relates to par-fried potato strips for subsequent finishing in an oven prior to consumption. The oven finished fries show a vast improvement in texture when compared to commercially prepared par-fries that have been oven finished.
French fries are one of the most popular convenience foods. A wide variety of French fried potato products are produced for both foodservice and home use. French fried potato strips, commonly referred to as "French fries" are served in most fast food restaurants. Most restaurants including large restaurants and consumers prefer to prepare the French fries from the frozen or chilled partially fried product (hereinafter par-fried) rather than go through the procedure of preparing French fries from raw potatoes. The par-fried potatoes are converted by the fast food restaurant or consumer into products such as French fried potatoes and the like.
The use of par-fried potato strips has been widely adopted in fast food restaurants because of the advantages they offer. A few of the recognized advantages associated with the use of frozen par-fried potato strips are, for example, users know the exact cost, the number of servings and the cost per portion. In addition, use of the frozen par-fried potatoes simplifies storage and inventory control, assures uniform quality from one season to another and reduces labor and time preparation for serving.
A major problem confronted by fast food restaurants is obtaining oven finished fries which have the taste and texture of fries finished by frying in hot oil. Important features of French fries finished by deep frying are interior moistness and crispness of the crust. However heretofore, achieving these product characteristics generally has not been possible when the products are oven finished. The oven finished products are typically leathery, tough, drier and less lubricious than French fries finished by frying in hot oil or they tend to be limp and soggy and do not have a crisp crust. These problems are recognized by the consumer and, more particularly, by fast food restaurant operators. As a result fast food restaurants seldom practice/use oven finishing techniques for preparing French fries.
Suppliers of frozen par-fried potato strips have proposed a number of solutions for improving the crispness of French fries which have been finished in an oven. For example, the surface treatment of potato strips with firming agents such as modified starches, gums, alginates, calcium salts, and the like. The majority of the methods for producing "finished baked fries" require coating the par-fried potato strip, see for example U.S. Pat. No. 3,865,964 (Kellermeir et al.), U.S. Pat. No. 5,000,970 and U.S. Pat. No. 4,913,296 (Shanbhag et al.), U.S. Pat. No. 5,279,840 (Baiser et al.) and U.S. Pat. No. 5,302,410 (Calder et al.).
The results obtained by surface treatment procedures, however, have been successful only to a limited degree. These processes may provide limited improvements in texture, however they do not provide frozen par-fried potato strips which, when oven-finished, have substantially the same texture as deep fried potato strips.
While not wishing to be bound by theory, it is believed that prior art oven fries lack the desirable surface crispness associated with high-quality deep-fried French fries in part because the oven fries are par-fried to relatively high moisture contents (e.g. .gtoreq.50% bulk moisture) prior to freezing. The limited amount of frying to yield a relatively high-moisture parfry results, upon oven finishing, in an oven fry that lacks a crust structure typical of deep-fried French fries. One approach for producing a crust in an oven fry that more closely simulates that of deep-fried French fries is to parfry the potato strips more extensively to a lower moisture content (e.g. .ltoreq.50% bulk moisture) so as to more fully develop the crust structure and thickness. While this approach may yield improved surface crispness upon oven finishing of the parfries, it also results in a significant driving force for moisture migration during frozen storage. The thicker, more developed low-moisture crust region of the resulting parfry has a relatively low water activity (Aw) and will, therefore, tend to act as a sink for the movement of water vapor away from the internal core of the parfry during frozen storage. Consequently, there is a potential that with an extended time of frozen storage (and/or fluctuating temperatures) the internal core of the fry will be dehydrated to such an extent that the oven-finished French fry will be perceived as having an unacceptably dry interior.
The present invention enables the production of par-fried potato strips that, upon oven-finishing, yield deep fried internal and surface textural properties. One aspect of the present invention is based in part on the surprising discovery that oven finished French fries that have substantially the same internal and surface texture as deep fried French Fries can be produced by reducing the amount of moisture transfer that occurs between the high-moisture internal starch matrix and the low-moisture crust region during frozen storage. This reduction in moisture transfer is accomplished by hydrating the outer surface of par-fried potato strips prior to frozen storage. As a result of this surface hydration step, parfried potato strips can be produced that have been fried more extensively to lower moisture contents (i.e. .ltoreq.50% moisture) to more fully develop the crust structure, and yet which are not subject to significant water movement from the fry interior to the crust region during frozen storage. The surface hydration step effectively increases the water activity of the outer crust region, thereby, greatly reducing or eliminating the water activity differential between the fry interior and crust region that is the driving force for moisture migration. Upon oven finishing, these hydrated parfries have a surface texture more like deepfried French fries because they have been parfried more extensively to develop the crust structure. In addition, the oven-finished fries have a desirable moist interior because the surface hydration step has minimized dehydration of the core during frozen storage. Net, the oven-finished French fries of the present invention possess both internal and surface textural attributes that closely simulate deep-fried French fries.
Another aspect of the present invention is based on the fact that the par-fries produced by the process disclosed herein, can be oven finished in substantially less time than commercially prepared fries intended for oven finishing.
Accordingly, it is an object of the present invention to provide a French fried product which when finish baked, closely resembles the internal and surface texture of deep fried fast food French Fries.
It is another object of the present invention to provide a par-fried frozen product which requires only a brief period of cooking before serving.
It is further an object of the present invention to provide a par-fried frozen product which can be finished in an oven of a fast food restaurant or in the consumer's home which is virtually indistinguishable from deep fried French fried potatoes.